I don't know if 'good' would be the word I would use but as far as nitrate tests go it's one I use routinely. The Salifert is the back up one for me. I don't much like them compared to my Red Sea Alk/Cal/Mg stuff but they're definitely effective.

@Brian Tesch deserves credit for this one as he's the one who tipped me off but I think this vendor deserves to be shown off in the club. You can custom order just about any macro from them. They offer different types of coralline algae and snails. Most importantly to me, they offer half a dozen beautiful gorgonian specimens. The icing on the cake is they also sell different types of sponges like ear/finger/ball. Items come in and out of stock almost daily. If it's not in stock, it will be shortly from what I've observed in the last couple weeks.
That's all well and good but here's the real reason I'm so excited to share it: they're dirt cheap, ship super fast and sell gigantic specimens. I love my sps but sea fans and sponges fascinate me but they're not the easiest things to source. Anyways, hope this doesn't violate any rules but I'm not affiliated in any way, just wanted to make some people aware that they are a legit option for these things.
Enjoy!
https://www.live-plants.com/index.htm
edit: Forgot one thing, they actually ship gorgonians in drilled frag plugs which is really handy. These things slough flesh off so keeping them glued or attached to anything can be a nightmare if they're not prepared this way. Thoughtful!